Electrical ignition system for internal-combustion engines.



. KRATZ,

ELECTRICAL IGMTION HYSPRM FOR IN'YETNAL CMBJSIION ENGINES.

Pn'mmted J am. 6, i914.

WITH 55555 mm3-Lf ter contacts are sutliciently extended .to procompleting at will the circuit including the y. UNTTED STATES PATENT OFFICE.

,FRANZ xRATz, or STUTTGART, GERMANY, AssiGNoR To'THE FIRM or 'ROBERT BOSCH,

.or STUTTGART, GERMANY.

Specification of Letters Patent.

Patented Jan. 6, 1914.

Application filed December 6, 1912. Serial No. 735,180.

To all whom it may con cern Be it known that I, FRANZ Km'rz, a subject .of the Emperor of Germany, residing at- Stuttgart, Germany, hare invented certain new and useful Improvements in Electrical Ignition Systems for Internal-Combustion Engines; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertainsto make and use the same.

The present invention relates to electrical ignitionsystems for internal Combustion engines, and more particularly to a system in which the apparatus for ignition during running is supplemented by such apparatus for starting the engine fromrest when' coinbustible mixture is present in a cylinder that its operation is independent of the position 0f rest 4of the mechanical interruptor. For this purpose it has heretofore been proposed to use a. battery and an electromagnetic interrupter having a 'vibratory armature connected in electrical series with a mechanical interruptor driven by the engine,`in combination with a manually operated switch for electromagnetic interruptor and the mechanical interrupter. Furthermore, it'has been proposed to render this prior system 4operative to'start the engine also from thaty position of rest in which the mechanical interrupter has an unfavorable position for this purpose by providing an auxiliary switch for closing the circuit of the electromagnetic interrupter independent-ly of the mechanical'interrnpter. In this latter arrangement, it is intended that the auxiliary/ switch should be released immediately after the engine has started, so that thereafter the mechanical interruptor may control the period of ionition and bring about the ignition of tie 'combustible mixture atthe retarded period to which the apparatus would be adjusted for starting` However, if this switch is held in its operative position after the engine has started, continual sparking occurs t .mgl it the entire interval in which a spark plat-3 is connected to the ig- ,f

nit-ion apparatus by the distributor, so that in the usual equipments, where the distribui videfor the extreme range of adjustment of ,the period of ignition, premature ignition i occurs, resulting in back fire and perhaps in the reversal of the engine.

ln accordance with the present invention the dillculty due to premature ignition is avoided by arranging the path toi-'completing the circuit. of the electromagnetic inlcrrupter independently of the mechanical interrupler in such manner as to include in a closed circuit'the winding of the electroniagnetic intcrrupter and a source of current, so thatwhenever this circuit is established, the vibiatory armature is attracted toa position to interrupt' the electrical'connection to the mechanical intcrrupter. In this way single sparking voltages are generated in the winding of the electromagnetic interrupter when the independent path is established and inl terrupted, while, after the engine has started, the mechanical interruptor is ctfectivc to control the period of connection, only when this independent path is interrupted. There- 75 fore, in accordance with my invention, if the engine has started and lheindepcndentpath is maintained closed, the ignitioiris in-` terrupted, and the engine may stop, but back-fire and reversal ot' the engine is avoid- 80 ed. Ilowever, it is intended that'the independent path should be permanently interrupted soon--atter th engine starts so that the mechanical interrupter may thereafter control the period ot ignition and cause the engine to speed up to its normal speed without danger of'back-tire aud reversal. Certain moditicatici'is of this broad idea are disclosed herein, wherebyl sparking voli-ages adapted to produce powerful sparks at the spark plugs are generated in the winding of the electromagnetic interrupter by the supplementary starting apparatus, and whereby the apparatus disclosed has practical ativantages in commercial application. However, it is to be understood that the idea einbodied herein may be attained by various other arrangements and by the use of other kinds of-apparatus, so that I limit myself only to the features within the broad interpretation of the appended claims.

In the accol'npanying drawings, illustrating the preferred embodiment of my invention, Figure l is a diagram ofthe circuits for a our-cylimler internal '-ombustion en,- gine, as an example; and Fig. l represents. diagrannnat-ically the apparatus for a single cylinder engine, as-an example, and shows the electromagnetic interrupter' and its associated parts.

In Fig. 1, the battery l is electrically connected to the primary winding of the electromagnetic interrupter by way of the switch 13, while the other terminal of the.y battery is electricallyconnected to one con` tact of the mechanical interruptor 6, which is driven from the engine in the well known way. The other contact of the mechanical interrpter is connected, yto the vibratory armature of the electromagnetic interrupter through the make and break contacts 3, 4. The contacts of the mechanical interrupter 6 are shunted by the condenser 7, andthe contacts 3, 4 are shunted by the condenser 7", for the urpose of suppressing the sparks thereat. ne. terminal of the secondary winding of the 'electromagnetic interrupter 2 is grounded, as shown, and the other terminal" thereof is connected to the rotatable brush of the distributer 8, which is driven from the-engine in the .well known way. The distributer contacts are connected to the individual spark plugs 9 mounted in and grounded to the separate cylinders of the engines in the usual manner.'A The manually operated switch 11 is arranged to short cir-I cuit the path through the mechanical linterrupter and to establish and interru t at will 'the' closed circuit, including the attery 1 ,and'the primary winding of the electromagnetyic interrupterl 2 by being connected cn one side to a terminal of the primary winding and on the other side to a, terminal of the 'battery as shown. The electrical resistance 12- is included in the short circuiting path for-the purpose of decreasing the flow ofcurrent from the battery through the low resistance primary winding of the electromagnetic interrupter when the switch 11 is I closed.

Fig. 2 shows the same arrangement as in Fig. 1, except that it is intended for a single v cylinder internal combustion engine having a. single spark plug 9, no distributer being required. The iron core of the electromagnetic interrupter 2 carries fthe primary and secondary windings, and also carries the rJ- sistance winding 12. The vibratory armature 'of the electromagnetic"interrupter is Y ing `with the contact 3 near the free end of fastened at one end to 'a stationary conducting support, which also carries a blade spring 5 of metal, provided at its other end with .one of the contacts of themanually operated switch 1 1. The'contact 4, coperatthe vibratory armature, passes `freely through an opening in the blade spring 5, and is held stationary in the -frame of the apparatus as indicated.

The operation of the arrangement is as follows :-If the 'coperating contacts of the'mechanical interrupter 6 are at rest in their closed position, then when it is desired to start the engine it is onl .necessary to close switch 1 3. -current rom the battery 1 passing through the primary .winding of tie electromagneticirrterrupter 2 causes its `vibratory `armature .to vibrate,

and thereby to rapidly interrupt 'and estab-A will be ignited, andthe engine .will start.'

The mechanical interrupter G and thedistributer 8 will then 'bc rotated with the engine and the normal cycle of operations or the engine will be initiated, the mechanical interrupter 6 controlling the period of ignition in accordance with the -adjustment of the spark adjusting mechanism., However, if in the arrangement shown in thedrawings, it is desired to start the engine fronrthat position of rest in which the copei'ating contacts'of the mechanical interruptor-:6 are separated, which position, may result from an improper balance of the englne parts or from other causes, closingswitch 13 will not establish an electrical circuit through the mechanical interrupter and no sparking voltages will be produced, although the rotatable brush will, under almost alll conditions, be in engagement with one 'of the distributed contacts, owing to the relatively extended contacts of the distributed parts,

as indicated'in Fig 1.. However, by the.

arrangement herein shown, the' engine may be started under these conditions by closing the switch' 11, and then o ening it, or by repeatedly'opening and closing switch 11 as required. When this switch 1l is closed,-

a .current-limited by the resistance 12, and also by the resistance of the primary winding of the electromagnetic interrupter 2, will flow through the circuit established by the independent -path containing the switch- 11, thereby charging the condensers 7* and 7* in series; A voltage will then beinduced' in the secondary winding of the electromagnetic interrupter 2,. but its value may not be sufficiently hi to produce a satisfactory ignition .spar r "at 'the. spark plug. Now,

when theswitch 11 isop'ened Vto interrupt the circuit, the current rapidly decreases to zero, especially in view of the discharge from'the condensers 7 and 7", and a single' voltage suitable for producin a spark at the spark plug 9 willie induced in the secondary winding. The combustible mixture present in that cylinder will be powerful l alongside of the ignited, and the engine will start, although in some cases'it may be desirable to repeat the operation of opening and closing the switch 1l. It will be observed that during the period in which the switch 11 is closed, the coperating contacts 3, 4, will be separated, owing` tothe fact that the Vibratory armature will remain attracted by the magnetized lcore of the electromagnetic interrupter, setlist the mechanical interruptorI is then rendered ine dective to control the generation of sparking voltages. However, it is intended that as soon as the engine has started, the switch 1l should be opened, so that the mechanical interrupter may thereafter become effective to produce sparking voltages at the ignition periods predetermined by the adjustment of the adjusting mechanism usually provided for this pur` poseq lf at any time during the starting or the running of the engine, the switch ll Should be closed, nothing more serious than stopping the engine would result, the danger of premature ignition, back-firing, or revers-alot the engine being obvifited by the arrangement set forth, while the engine would continue its operation with its ignition under control. -of the mechanical interruptor as soon as the switch was released.

By winding the resistance 12 on the electromagnetic interruptor, above, below or primary winding, or in a single layer on t ie 'secondary winding, as indicated at 12 in Fig. 2, or by Winding the resistance around one of the condensers, a compact and commercial arrangement of these parts is secured.

Having thus described my invention, what l claim is 1. In. an electrical ignition system for internal combustion engines; the combination ot apparatus for ignition during running, including a sourceiof electric current; an electromagnetic interruptor having a winding and a vibratory armature.; a mechanical interruptor driven from the engine; and electrical connections therefor; of supplementary apparatus for starting the engine from rest by ignition when the mechanical interruptor' has such a position as to render the ignition system for running ineffective for starting, including a switch and elec trical connections for establishing and interrupting a supplementary circuit' which includes the source of current and the winding of the electromagnetic interruptor; the arrangement being such that as long as the supplementary circuit is established, the mechanical interruptor is disconnected. by' the vibratory armature so that the operation ot the mechanical interruptor is then rendered ineffective 'for producing sparking voltages in the Winding, and such that when the supplementary circuit is interrupted, the operation ofthe mechanical'interruption is effective for that purpose; substantially as described.

i2. In an electrical ignition system for internal combustion engines; the combination with apparatus for ignition ,during running including a source of electric current; an electromagnetic interruptor having a winding and a vibrator-y armature; a mechanical interruptor driven from thc engine; and electrical connections therefor; of supplementary apparatus arranged to start the engine from rest by ignition when the mechanical interruptor has such a position as to render the ignition apparatlus for ruiming ineffective for starting, including a switchand electric connections arranged in electrical parallel with the mechanical interruptor so as to establish and interrupt a supplementary cir cuit including the source of current and the winding, but excluding the vibratory armature and the mechanical interruptor; substantially as described.

3. In an electric ignition system for internal combustion engines; the combination with apparatus for ignition during ruiming, including a source of electric current; an electromagnetic interruptor having a Winding and a vibratory armature; a mechanical interrupter driven from the engine; and electrical connections therefor of su pplementary apparatus arranged to start the engine from rest by ignition when the mechanical interrupter has suoli a position as to' render the ignition apparatus for running ineffective foi sta1tin g, including a resistance, and electrical connections arranged in shunt to the vibratory armature andthe mechanical interrupt-er so as to establish and interrupt a supplementary circuit including thc source of current, the winding, and the resistance; substantially as described.

et. In an elect-ric ignition system for internal `combustion engines; the combina-tion with apparatus for ignition during running, 'including a source of electric current; an electromagnetic interruptor having a' Winding and avibratouy armature; a mechanical interruptor driven from the engine and connected in electrical series with the vibratory armature; and electricalconnections therefor; of supplementary apparatus tor starting the engine fromy rest by ignition when the mechanical interruptor is open, including a switch, a resistance and electrical connections arranged to'establish and interrupt a supplementarp1 circuit including the source of current, the Winding, and the resistance, but excluding the vibrntory armature and the mechanical interrupter; substantially as described.

5. ln an electric ignition system4 for internal combustion engines; the combination with apparatus for ignition during running, including a source of electric current; an electromagnetic interrupter having a vvinding in series with a vibratory armature; a

mechanical interrupter driven from the cngine and electrically connected to the vibratory armature through make-and-break contacts; a condenser shunted around the makeand-break contacts; a condenser shnnted around the cooperating contacts of the mechanical interrupter; and electrical connections therefor; of apparatus forstarting the engine from rest by ignition when the mechanical nterrupter has such a position as to render the ignition apparatus for running ineffective for starting, including a switch and electrical connections arranged to establish and interrupt a supplementary circuit including the source of cui-rent and the Winding7 tle arrangement being such that the condensers are shunted in series across said switch; substantially as described.

(3. In an electrical ignition system for internal combustion engines; the combinati 'i with apparatus for ignition during ruiming, including a source of electric' current;` `lm electromagnetic interruptor having a Winding in series with a vibratory armature; a mechanical interruptor driven from the engine and electrically connected to the vibra tory armature through make-and-break contacts; a condenser sllunted around the makeand-break contacts; a condenser shunted around the cooperating contacts of the Inechanical interruptor; and electrical connections therefor; of apparatus for starting the engine from rest by ignition when the mechanical interrupter has such a position as to render the ignition apparatus for running inefective for starting, including a switch, a resistance, and electrical connec tions arranged to establish and interrupt a supplementary circuit including the source of current, the winding of the electromagnetic interrupter and the resistance, the ai rangement being such that the condensers are shuntedl in series across said switch; substantially as described.

In testimon whereof I aflix my signature, in presence o two Witnesses.

FRANZ KRATZ.

fitnesses z PAUL VoLron'r, HERMANN SCHNEIDER. 

